diff --git a/reactos/dll/win32/rpcrt4/cproxy.c b/reactos/dll/win32/rpcrt4/cproxy.c
index 26e5c416c9c..084285a5458 100644
--- a/reactos/dll/win32/rpcrt4/cproxy.c
+++ b/reactos/dll/win32/rpcrt4/cproxy.c
@@ -56,7 +56,7 @@ typedef struct {
 
 static const IRpcProxyBufferVtbl StdProxy_Vtbl;
 
-#define ICOM_THIS_MULTI(impl,field,iface) impl* const This=(impl*)((char*)(iface) - FIELD_OFFSET(impl,field))
+#define ICOM_THIS_MULTI(impl,field,iface) impl* const This=(impl*)((char*)(iface) - offsetof(impl,field))
 
 /* How the Windows stubless proxy thunks work is explained at
  * http://msdn.microsoft.com/library/en-us/dnmsj99/html/com0199.asp,
diff --git a/reactos/dll/win32/rpcrt4/cstub.c b/reactos/dll/win32/rpcrt4/cstub.c
index cd07c297390..d0b24c98dfb 100644
--- a/reactos/dll/win32/rpcrt4/cstub.c
+++ b/reactos/dll/win32/rpcrt4/cstub.c
@@ -194,7 +194,7 @@ static void fill_table(IUnknownVtbl *vtbl, void **methods, DWORD num)
 #else  /* __i386__ */
 
 typedef struct {int dummy;} vtbl_method_t;
-static void fill_table(IUnknownVtbl *vtbl, DWORD num)
+static void fill_table(IUnknownVtbl *vtbl, void **methods, DWORD num)
 {
     ERR("delegated stubs are not supported on this architecture\n");
 }
diff --git a/reactos/dll/win32/rpcrt4/rpcrt4.rbuild b/reactos/dll/win32/rpcrt4/rpcrt4.rbuild
index 092e9f17986..25ab4113d00 100644
--- a/reactos/dll/win32/rpcrt4/rpcrt4.rbuild
+++ b/reactos/dll/win32/rpcrt4/rpcrt4.rbuild
@@ -7,7 +7,6 @@
 	<define name="_WIN32_IE">0x600</define>
 	<define name="_WIN32_WINNT">0x501</define>
 	<define name="WINVER">0x501</define>
-	<define name="_STDDEF_H" />
 	<define name="_RPCRT4_" />
 	<define name="COM_NO_WINDOWS_H" />
 	<define name="MSWMSG" />